U.S. patent application number 11/280162 was filed with the patent office on 2007-01-04 for methods and system for inhibiting immersion lithography defect formation.
This patent application is currently assigned to Taiwan Semiconductor Manufacturing Company, Ltd.. Invention is credited to Ching-Yu Chang, Burn Jeng Lin.
Application Number | 20070004182 11/280162 |
Document ID | / |
Family ID | 37590153 |
Filed Date | 2007-01-04 |
United States Patent
Application |
20070004182 |
Kind Code |
A1 |
Chang; Ching-Yu ; et
al. |
January 4, 2007 |
Methods and system for inhibiting immersion lithography defect
formation
Abstract
An immersion lithography system includes an immersion fluid
holder for containing an immersion fluid. The system further
includes a stage for positioning a resist-coated semiconductor
wafer in the immersion fluid holder and a lens proximate to the
immersion fluid holder and positionable for projecting an image
through the immersion fluid and onto the resist-coated
semiconductor wafer. The immersion fluid holder includes a coating
configured to reduce contaminate adhesion from contaminates in the
immersion fluid.
Inventors: |
Chang; Ching-Yu; (Yilang
City, TW) ; Lin; Burn Jeng; (Hsin-Chu, TW) |
Correspondence
Address: |
HAYNES AND BOONE, LLP
901 MAIN STREET, SUITE 3100
DALLAS
TX
75202
US
|
Assignee: |
Taiwan Semiconductor Manufacturing
Company, Ltd.
Hsin-Chu
TW
|
Family ID: |
37590153 |
Appl. No.: |
11/280162 |
Filed: |
November 16, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60695825 |
Jun 30, 2005 |
|
|
|
Current U.S.
Class: |
438/478 ;
438/947 |
Current CPC
Class: |
G03F 7/70925 20130101;
G03F 7/70341 20130101; G03F 7/70916 20130101 |
Class at
Publication: |
438/478 ;
438/947 |
International
Class: |
H01L 21/20 20060101
H01L021/20; H01L 21/36 20060101 H01L021/36 |
Claims
1. A method for performing immersion lithography, comprising:
coating one or more surfaces of an immersion lithography system
with a hydrophilic coating, the one or more surfaces for containing
an immersion fluid; providing the immersion fluid to the immersion
lithography system; performing immersion lithography on a
resist-coated substrate using the immersion lithography system with
the one or more hydrophilic coated surfaces.
2. The method of claim 1 wherein the hydrophilic coating is
selected from the group consisting of: (i) silicon dioxide; (ii)
polytetrafluoroethylene; (iii) fluoride; (iv) polyethylene; (v)
polyvinylchloride; (vi) polymers of at least one of the materials
(i)-(v) above; (vii) alloys of at least one of the materials
(i)-(v) above; and (viii) combinations containing at least one of
the materials (i)-(v) above.
3. The method of claim 1 wherein the resist-coated substrate is a
semiconductor wafer.
4. The method of claim 1 wherein the immersion lithography system
includes a wafer stage, an immersion fluid holder, and a lens, and
at least a portion of the immersion fluid holder is coated with the
hydrophilic coating.
5. The method of claim 4 wherein each of the wafer stage, immersion
fluid holder, and lens are coated with the hydrophilic coating.
6. The method of claim 4 further comprising: cleaning at least a
portion of at least one of the wafer stage, the immersion fluid
holder, and the lens of the immersion exposure apparatus after
performing the immersion lithography.
7. The method of claim 4 further comprising: cleaning at least a
portion of at least one of the wafer stage, the immersion fluid
holder, and the lens of the immersion exposure apparatus when a
value sensed by a sensor exceeds a predetermined threshold.
8. The method of claim 4 further comprising: cleaning at least a
portion of at least one of the wafer stage, the immersion fluid
holder, and the lens of the immersion exposure apparatus using a
chemical cleaning solution and a surfactant solution.
9. The method of claim 8, wherein the chemical cleaning solution
includes at least one of ammonia, hydrogen peroxide, ozone,
sulfurous acid, and compositions thereof.
10. The method of claim 8, wherein the surfactant solution includes
at least one of an ionic surfactant and a non-ionic surfactant.
11. An immersion lithography system comprising: an immersion fluid
containment chamber including a plurality of surfaces; an immersion
fluid positioned in the immersion fluid containment chamber; a
substrate stage positioned within the immersion fluid chamber; a
lens; and a reduced-contaminate-adhesion coating applied to one or
more of the plurality of surfaces.
12. The immersion lithography system of claim 11 wherein the
reduced-contaminate-adhesion coating is selected from the group
consisting of: (i) silicon dioxide; (ii) polytetrafluoroethylene;
(iii) fluoride; (iv) polyethylene; (v) polyvinylchloride; (vi)
polymers of at least one of the materials (i)-(v) above; (vii)
alloys of at least one of the materials (i)-(v) above; and (viii)
combinations containing at least one of the materials (i)-(v)
above.
13. The immersion lithography system of claim 11 wherein the
substrate stage is configured for holding a resist-coated
semiconductor wafer.
14. The immersion lithography system of claim 11 further
comprising: a reduced-contaminate-adhesion coating applied to at
least a portion of the substrate stage.
15. The immersion lithography system of claim 11 further
comprising: a reduced-contaminate-adhesion coating applied to at
least a portion of the lens.
16. The immersion lithography system of claim 11 further
comprising: a mechanism for providing a cleaning solution to the
immersion fluid containment chamber.
17. The immersion lithography system of claim 16 further
comprising: a sensor for detecting when the cleaning solution
should be provided to the immersion fluid containment chamber.
18. The immersion lithography system of claim 16, wherein the
cleaning solution includes at least one of ammonia, hydrogen
peroxide, ozone, sulfurous acid, and compositions thereof.
19. The immersion lithography system of claim 16, wherein the
cleaning solution includes at least one of an ionic surfactant and
a non-ionic surfactant.
20. An immersion lithography system comprising: an immersion fluid
holder for containing an immersion fluid; a stage for positioning a
resist-coated semiconductor wafer in the immersion fluid holder; a
sensor proximate to the immersion fluid holder; and a lens
proximate to the immersion fluid holder and positionable for
projecting an image through the immersion fluid and onto the
resist-coated semiconductor wafer; wherein the immersion fluid
holder includes a coating configured to reduce contaminate adhesion
from contaminates in the immersion fluid.
21. The immersion lithography system of claim 20, wherein the
coating includes a property for increasing a wettability of a
surface of the immersion fluid holder that is adjacent to the
immersion fluid.
22. An apparatus comprising: a plurality of components collectively
operable to perform immersion lithography, the plurality of
components including one or more components selected from the group
consisting of: a wafer stage, an immersion fluid holder, a sensor,
and a lens; wherein at least a portion of at least one of the
plurality of immersion exposure apparatus components has an
exterior coating configured to have a contact angle larger than
about 50 degrees.
23. The apparatus of claim 22, wherein the coating is selected from
the group consisting of: (i) silicon dioxide; (ii)
polytetrafluoroethylene; (iii) fluoride; (iv) polyethylene; (v)
polyvinylchloride; (vi) polymers of at least one of the materials
(i)-(v) above; (vii) alloys of at least one of the materials
(i)-(v) above; and (viii) combinations containing at least one of
the materials (i)-(v) above.
Description
CROSS-REFERENCE
[0001] This application claims priority from U.S. Provisional
Patent Application Ser. No. 60/695,825, filed on Jun. 30, 2005, and
entitled "METHODS AND SYSTEM FOR INHIBITING IMMERSION LITHOGRAPHY
DEFECT FORMATION."
BACKGROUND
[0002] Immersion lithography typically involves applying a coating
of photoresist on a top surface (e.g., a thin film stack) of a
semiconductor wafer and subsequently exposing the photoresist to a
pattern. During exposure, de-ionized (DI) water may be used to fill
the space between the exposure lens and the resist surface to
increase the depth of focus (DOF) window. One or more post-exposure
bakes and/or other processes may then be performed, such as to
allow the exposed photoresist to cleave (such as when the
photoresist comprises a polymer-based substance), to densify the
polymer, and/or to evaporate any solvent, among other possible
objectives. A developing chamber may then be employed to remove
exposed polymer, which can be soluble to an aqueous developer
solution, possibly after application of tetra-methyl ammonium
hydroxide (TMAH). A DI water rinse may then be applied to remove
the water-soluble polymer or other dissolved photoresist, and a
spin dry process may be used to dry the wafer. The exposed and
developed wafer may then be transferred for subsequent processing
operations, although possibly after additional baking to evaporate
moisture on the resist surface.
[0003] Immersion lithography apparatus may comprise an immersion
scanner DI chamber, which may include a lens system, a DI water
holder system around the lens, a sensor system and/or a wafer stage
system, among other possible components. Portions of the lens
apparatus may be composed of silica, silicon dioxide and/or similar
materials, and/or may have one or more layers of silica, silicon
dioxide and/or similar materials coated thereon. The stage system
may be composed of an alloy of aluminum, silica, silicon,
magnesium, zinc, phosphorus, and/or oxygen. The sensor system
surface may be coated with titanium nitride. The DI water holder
system may be composed of stainless steel.
[0004] The above-described processing/apparatus can be encumbered
by several problems. For example, the resist surface zeta potential
can be about -40 mV at PH=7 (zeta potential may refer to the
electrical potential that exists across the interface of a solid
and a liquid, or the potential of a solid surface interacting with
an ambient featuring a specific chemical composition, and may also
be referred to as electrokinetic potential). Consequently, if the
immersion DI fluid contains contaminates, the contaminates may
adhere to the resist surface. Similarly, the silica, silicon
dioxide or similar material of the lens and/or lens apparatus may
have a zeta potential of about -25 mV, which can be weaker than the
resist surface, thus possibly attracting contaminants. The alloyed
material of the stage may contain at least one aluminum element or
component which may have a +40 mV zeta potential, such that its
surfaces may easily adhere negative zeta potential particles. The
stainless steel of the DI water holder system may also have a
positive zeta potential, such that negative zeta potential
particles may adhere thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Aspects of the present disclosure are best understood from
the following detailed description when read with the accompanying
figures. It is emphasized that, in accordance with the standard
practice in the industry, various features may not be drawn to
scale. In fact, the dimensions of the various features may be
arbitrarily increased or reduced for clarity of discussion.
[0006] FIGS. 1 and 2 are sectional views of a wafer being processed
by conventional immersion lithography methods/apparatus.
[0007] FIG. 3 illustrates several exemplary defects on a wafer
which may result from conventional immersion lithography
methods/apparatus.
[0008] FIGS. A-F graphically depict relationships between zeta
potential and pH for various compositions/wafers.
[0009] FIG. 4 depicts a contact angle of about 20 degrees of a
fluid such as de-ionized water on a surface coated with silicon
dioxide.
[0010] FIG. 5 depicts a contact angle of about 90 degrees of a
fluid such as de-ionized water on a surface coated with PTFE or
polytetrafluoroethylene.
[0011] FIGS. 6 and 7 are sectional views of a wafer being processed
by conventional immersion lithography methods/apparatus.
[0012] FIGS. 8 and 9 are sectional views of a wafer being processed
by one embodiment of immersion lithography apparatus according to
aspects of the present disclosure.
[0013] FIG. 10 is a flow chart of at least a portion of one
embodiment of a method for implementing an immersion lithography
process with reduced defects according to aspects of the present
disclosure.
DETAILED DESCRIPTION
[0014] The entire disclosures of the following patents are hereby
incorporated herein by reference: [0015] (1) U.S. Pat. No.
6,867,884; [0016] (2) U.S. Pat. No. 6,809,794; [0017] (3) U.S. Pat.
No. 6,788,477; [0018] (4) U.S. Pat. No. 5,879,577; [0019] (5) U.S.
Pat. No. 6,114,747; and [0020] (6) U.S. Pat. No. 6,516,815.
[0021] The entire disclosures of the following U.S. patent
applications related hereto and commonly assigned herewith are also
hereby incorporated herein by reference: [0022] (7) U.S. Ser. No.
10/995,693, entitled "Immersion Photolithography With Megasonic
Rinse," Attorney Docket No. 24061.536; [0023] (8) U.S. Ser. No.
11/025,538, entitled "Supercritical Developing For A Lithographic
Process," Attorney Docket No. 24061.565; [0024] (9) U.S. Ser. No.
60/695,562, entitled "Immersion Lithography Defect Reduction,"
Attorney Docket No. 24061.656; and [0025] (10) U.S. Ser. No.
60/695,826, entitled "Immersion Lithography Defect Reduction,"
Attorney Docket No. 24061.657.
[0026] It is to be understood that the following disclosure
provides many different embodiments, or examples, for implementing
different features of various embodiments. Specific examples of
components and arrangements are described below to simplify the
present disclosure. These are, of course, merely examples and are
not intended to be limiting. In addition, the present disclosure
may repeat reference numerals and/or letters in the various
examples. This repetition is for the purpose of simplicity and
clarity and does not in itself dictate a relationship between the
various embodiments and/or configurations discussed. Moreover, the
formation of a first feature over or on a second feature in the
description that follows may include embodiments in which the first
and second features are formed in direct contact, and may also
include embodiments in which additional features may be formed
interposing the first and second features, such that the first and
second features may not be in direct contact.
[0027] Referring to FIGS. 1 and 2, illustrated are sectional views
of conventional immersion lithography apparatus 100 in which
different regions of a semiconductor wafer 110 is undergoing
immersion lithography processing. The semiconductor wafer 110 may
include a substrate and a patterning layer. The substrate can
include one or more layers, including poly, metal, and/or
dielectric, that are desired to be patterned. The patterning layer
can be a photoresist (resist) layer that is responsive to an
exposure process for creating patterns.
[0028] The illustrated example of the immersion lithography
apparatus 100 includes a lens system 122, a structure 124 for
containing an immersion fluid 126 such as de-ionized water, various
apertures 128 through which fluid can be added or removed, and a
stage 130 and fixture 132 (such as a chuck, and which may be
integral to the stage 130) for securing and moving the wafer 110
relative to the lens system 122. The immersion fluid containing
structure 124 and the lens system 122 make up an immersion head
120a. The immersion head 120a can use some of the apertures 128 as
an "air knife" which can purge air into the wafer for drying, and
other apertures for removing any purged fluid. The air knife alone
may be insufficient to purge all of the immersion fluid 126 from
the wafer 110.
[0029] FIG. 3 includes a top view of the wafer 110 after undergoing
conventional immersion lithography processing, such as via
processing in the apparatus 100 shown in FIGS. 1 and 2. FIG. 3 also
includes several detail views of defects 150 that may form on the
wafer 110 during the processing in the apparatus 100. The defects
can represent watermarks, residue or foreign particles in the
patterned resist, or can represent deformation or "holes" (missing
patterns) in the resist. Other types of defects may also exist. It
is noted that if post-exposure bake (PEB) is increased in time or
temperature to remove the watermark type defect, the likelihood of
foreign particles and/or other defects may increase.
[0030] FIGS. 6 and 7 are additional sectional views of the
apparatus 100 shown in FIGS. 1 and 2 and the wafer 110 shown in
FIGS. 1-3. As described above, the composition or surface
characteristics of one or more components of the apparatus 100 can
have an affinity to adhere contaminates. For example, the silica or
silicon dioxide composition of the stage 130 may have a relatively
low contact angle (see FIG. 4) or be hydrophilic, such that
particulate, water droplets 155 (possibly containing particulate),
and/or other contaminates can adhere to surfaces of the stage 130.
The composition, contact angle, affinity to water, and/or other
aspects of the stage 130, fixture 132, lens 122, structure 124,
and/or other components of the apparatus 100 may similarly render
the surfaces thereof as being prone to the adherence of
contaminates.
[0031] Referring to FIGS. 8 and 9, illustrated are sectional views
of at least a portion of one embodiment of apparatus 200 according
to aspects of the present disclosure. The apparatus 200 may be
substantially similar to embodiments of the apparatus 100 shown in
FIGS. 1, 2, 6 and 7. However, in the apparatus 200, a coating,
lining or other layer 210 exists on one or more surfaces of one or
more components of the apparatus 200. For example, one or more
surfaces of the lens 122 may include the coating 210. In one
embodiment, several or all surfaces of the lens 122 includes the
coating 210, except possibly for the surfaces (e.g., top and
bottom) through which exposure light propagates. One or more
surfaces of the stage 130, the fixture 132, the immersion fluid
containing structure 124, and/or the apertures 128 may also or
alternatively include the coating 210. In one embodiment, all
surfaces of all components of the apparatus 200 which may come in
contact with the immersion fluid 126 (except possibly for the
light-propagating surfaces of the lens 122) may include the coating
210.
[0032] The coating 210 may comprise one or more layers of silicon
dioxide, polytetrafluoroethylene ("PTFE", or TEFLON as provided by
the DuPont Corp.), fluoride, polyethylene, polyvinylchloride,
polymers of at least one of such materials, alloys of at least one
of such materials, combinations containing at least one of such
materials, and/or other polymers, among other compositions within
the scope of the present disclosure. The coating 210 may be
referred to as a "hydrophilic coating" because it provides improved
wettability. In addition or in the alternative, the coating can be
referred to as a "reduced-contaminate-adhesion coating" because it
decreases the adhesion of contaminates in the water to the
corresponding surface. The coating 210 may be formed on the
surfaces of the components of the apparatus 200 by one or more of
myriad conventional and/or future-developed processes, such as
chemical vapor deposition (CVD), dipping, brushing, spraying,
stamping, casting, bonding, spin-on coating, electrodeposition, and
others. The thickness of the coating 210 may vary within the scope
of the present disclosure. Moreover, the thickness, composition,
application process(es), and/or other aspects of the coating 210
may vary within a single embodiment. For example, the thickness and
composition of the coating 210 on one component of the apparatus
200 may vary from the thickness and composition of the coating on
another component of the apparatus 200.
[0033] As illustrated in the embodiment shown in FIGS. 8 and 9, the
apparatus 200 may also include one or more sensors or a sensor
system (herein referred to collectively as "sensor") 160. The
sensor 160 may be configured to detect contamination levels of
immersion fluid 126, rinsing agents and/or other fluids/gases,
numbers of cycles of exposure, number of cycles of filling and
evacuating the immersion fluid containing structure 124,
contamination levels of the substrate 110, and/or other
characteristics, qualities, measurements, or aspects, which may be
employed to assess the need to clean, filter, maintain and/or
replace components of the apparatus 200 and/or fluid/gas sources
(such as an immersion fluid source). The sensor 160 may be coupled
to or integral to the immersion fluid containing structure 124, as
in the illustrated embodiment. However, the sensor 160 may also or
alternatively be integral to, or directly or indirectly coupled to,
another component of the apparatus 200, such as the stage 130, the
immersion head 120a, and/or the fixture 132, among other
components. The sensor 160 may also include the exterior coating
210.
[0034] Referring to FIG. 10, illustrated is a flow-chart diagram of
at least a portion of one embodiment of a method 300 for immersion
lithography according to aspects of the present disclosure. In step
304, a resist is formed over the surface of a wafer substrate. The
resist may be a negative or positive resist and may be of a
material now known or later developed for this purpose. For
example, the resist may be a one-, two- or multi-component resist
system. The application of the resist may be done with spin-coating
or another suitable procedure. Prior to the application of the
resist, the wafer may be first processed to prepare it for the
photolithography process. For example, the wafer may be cleaned,
dried and/or coated with an adhesion-promoting material prior to
the application of the resist.
[0035] At step 306, the immersion exposure step is performed. The
wafer and resist are immersed in an immersion exposure liquid such
as de-ionized water, and exposed to a radiation source through a
lens. The radiation source may be an ultraviolet light source, for
example a krypton fluoride (KrF, 248 nm), argon fluoride (ArF, 193
nm), or F2 (157 nm) excimer laser. The wafer is exposed to the
radiation for a predetermined amount of time is dependent on the
type of resist used, the intensity of the ultraviolet light source,
and/or other factors. The exposure time may last from about 0.2
seconds to about 30 seconds, for example.
[0036] At step 308, a drying process is performed. The drying
process may be performed in-situ with the previous or next
processing step, or may be performed in a separate chamber. One or
more drying processes can by used individually or in various
combinations. For example, one or more liquids can be added for the
drying process, such as supercritical CO.sub.2, alcohol (e.g.,
methanol, ethanol, isopropanol (IPA), and/or xylene), surfactants,
and/or clean de-ionized water. Alternatively, or additionally, one
or more gases can be added for the drying step 308, such as
condensed/clean dry air (CDA), N.sub.2, or Ar for a purge dry
process. Vacuum processing and/or spin-dry processing can
alternatively or additionally be used to facilitate drying.
Spin-dry processing works especially well in combination with one
or more of the other above-listed drying processes, and may be
performed in-situ. For example, a de-ionized water rinse can be
dispensed through a nozzle to dissolve and/or clean any dirty fluid
droplets, either contemporaneously with or followed immediately by
a spin dry process.
[0037] At step 310, the wafer with the exposed and dry resist is
heated for a post-exposure bake (PEB) for polymer dissolution. This
step lets the exposed photo acid react with the polymer and make
the polymer dissolution. The wafer may be heated to a temperature
ranging between about 85.degree. C. and about 150.degree. C.,
possibly for a duration ranging between about 30 second and about
200 seconds, although other temperatures and durations are also
within the scope of the preset disclosure. In some embodiments, the
PEB step 310 can be preceded by a first lower-temperature bake
(e.g., 80% of the temperature described above), which may help
remove some of the existing fluid from the wafer.
[0038] At step 312, a pattern developing process is performed on
the exposed (positive) or unexposed (negative) resist to leave the
desired mask pattern. In some embodiments, the wafer is immersed in
a developer liquid for a predetermined amount of time during which
a portion of the resist is dissolved and removed. The wafer may be
immersed in the developer solution for about 5 to about 60 seconds,
for example. The composition of the developer solution is dependent
on the composition of the resist, and is understood to be well
known in the art.
[0039] The method 300 may also include one or more cleaning steps
302 prior to the resist form step 304 and/or one or more cleaning
steps 314 after the develop step 312. For example, such optional
step(s) may include cleaning at least a portion of at least one of
the wafer stage, the immersion fluid (e.g., DI water) holder, a
sensor, the lens and another component of the immersion exposure
apparatus. The cleaning may employ a chemical cleaning solution
including at least one of ammonia, hydrogen peroxide, ozone,
sulfurous acid, and compositions thereof. Additionally, or
alternatively, the cleaning may employ a surfactant solution
including at least one of an ionic surfactant and a non-ionic
surfactant. The cleaning steps 302 and/or 314 may be performed
between each exposure, or on an as needed basis. The cleaning steps
302 and/or 314 may additionally or alternatively be performed at
regular intervals, such as after a predetermined number of wafers
processed by the lens, a predetermined number of cycles of filling
and evacuation of the immersion fluid holder, or a predetermined
number of exposures with the lens. The cleaning steps 302 and/or
314 may additionally or alternatively be performed when a
measurement, characteristic, aspect or value sensed by a sensor
exceeds a predetermined threshold, falls below a predetermined
threshold, or otherwise satisfies a predetermined condition.
[0040] Thus, the present disclosure introduces an apparatus that is
or includes an immersion exposure apparatus having, at least in one
embodiment, a wafer stage, an immersion fluid (e.g., DI water)
holder, a sensor and a lens, among other possible components. At
least a portion of at least one of the wafer stage, the immersion
fluid holder, the sensor, the lens and/or another component of the
immersion exposure apparatus has an exterior coating selected from
the group consisting of: (i) silicon dioxide; (ii) PTFE; (iii)
fluoride; (iv) polyethylene; (v) polyvinylchloride; (vi) polymers
of at least one of these materials; (vii) alloys of at least one of
these materials; (viii) combinations containing at least one of
these materials; and (ix) other polymers. Methods of making,
manufacturing, using, operating or cleaning at least a portion of
such apparatus are also within the scope of the present
disclosure.
[0041] One embodiment of an apparatus constructed according to
aspects of the present disclosure includes a plurality of
components collectively operable or configured to perform immersion
lithography, where the plurality of components includes one or more
of a wafer stage, an immersion fluid (e.g., DI water) holder, a
sensor, and a lens, among other possible components. At least a
portion (e.g., one or more surfaces or regions thereon) of at least
one of the plurality of components has an exterior coating
configured to reduce contaminate adhesion. For example, the
exterior coating may increase the contact angle of surfaces having
the exterior coating, increase the degree to which surfaces having
the exterior coating are hydrophilic, and/or decrease the degree to
which surfaces having the exterior coating are hydrophobic.
[0042] The present disclosure also introduces a method including,
at least in one embodiment, forming a photoresist (or resist) layer
over a substrate, exposing the photoresist layer using immersion
exposure apparatus, baking the exposed photoresist layer, and
developing the baked, exposed photoresist layer. The immersion
exposure apparatus includes a wafer stage, an immersion fluid
(e.g., DI water) holder, a sensor and a lens. At least a portion of
at least one of the wafer stage, the immersion fluid holder, the
sensor and the lens has an exterior coating selected of silicon
dioxide, PTFE, fluoride, polyethylene, polyvinylchloride, polymers
of at least one of these materials, alloys of at least one of these
materials, combinations containing at least one of these materials,
and/or other polymers.
[0043] Embodiments of such a method may be performed for immersion
lithography with reduced defect contamination. The method may also
include cleaning at least a portion of at least one of the wafer
stage, the DI water holder, the sensor, the lens and/or another
component of the immersion exposure apparatus. The present
disclosure also provides embodiments of apparatus operable or
configured to perform at least a portion of at least one of the
above methods.
[0044] One or more aspects of one or more embodiments of methods
and/or apparatus within the scope of the present disclosure may
render the immersion lens chamber free from defect adhesion, or
decreased defect adhesion. One or more such aspects can
additionally or alternatively decrease cross contamination among
the lens, the resist, sensors, the stage, and/or the immersion
fluid holder. One or more such aspects can additionally or
alternatively decrease apparatus maintenance frequency and/or
complexity. One or more such aspects can additionally or
alternatively render the resist surface free from defects and/or
watermark contamination, or reduce defects and/or watermark
contamination. One or more such aspects can additionally or
alternatively extend or increase wafer scan speed, possibly
improving throughput. One or more such aspects can additionally or
alternatively decrease or release resilient leaching spec. One or
more such aspects can additionally or alternatively reduce or
eliminate the need for TAR coating, and/or reduce TARC processing
and associated cost and throughput.
[0045] Although embodiments of the present disclosure have been
described in detail, those skilled in the art should understand
that they can make various changes, substitutions and alterations
herein without departing from the spirit and scope of the present
disclosure.
* * * * *